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"Seddon, James A"
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Global burden of drug-resistant tuberculosis in children: a mathematical modelling study
by
Sismanidis, Charalambos
,
Dodd, Peter J
,
Seddon, James A
in
Antitubercular Agents - therapeutic use
,
Budgets
,
Child
2016
After infection with Mycobacterium tuberculosis, children are at an increased risk of progression to tuberculosis disease; a condition that can be challenging to diagnose. New estimation approaches for children have highlighted the gap between incidence and notifications of M tuberculosis, and suggest there are more cases of isoniazid-resistant and multidrug-resistant (MDR) disease than are identified. No work has yet quantified the burden of drug-resistant infection, or accounted for other types of drug resistance or sampling uncertainty.
We combined a mathematical model of tuberculosis in children with an analysis of drug-resistance patterns to produce country-level, regional, and global estimates of drug-resistant infection and disease. We determined drug resistance using data from the Global Project on Antituberculosis Drug Resistance Surveillance at WHO, from surveys and surveillance reported between 1988 and 2014. We combined 1000 sampled proportions for each country from a Bayesian approach with 10 000 sampled country estimates of tuberculosis disease incidence and M tuberculosis infection prevalence. We estimated the proportions of tuberculosis cases at a country level with isoniazid monoresistance, rifampicin monoresistance, multidrug resistance (MDR), fluoroquinolone-resistant multidrug resistance, second-line injectable-resistant multidrug resistance, and extensive multidrug resistance with resistance to both a fluoroquinolone and a second-line injectable (XDR).
We estimated that 850 000 children developed tuberculosis in 2014; 58 000 with isoniazid-monoresistant tuberculosis, 25 000 with MDR tuberculosis, and 1200 with XDR tuberculosis. We estimate 67 million children are infected with M tuberculosis; 5 million with isoniazid monoresistance, 2 million with MDR, and 100 000 with XDR. Africa and southeast Asia have the highest numbers of children with tuberculosis, but the WHO Eastern Mediterranean region, European region, and Western Pacific region also contribute substantially to the burden of drug-resistant tuberculosis because of their much higher proportions of resistance.
Far more drug-resistant tuberculosis occurs in children than is diagnosed, and there is a large pool of drug-resistant infection. This finding has implications for approaches to empirical treatment and preventive therapy in some regions of the world.
UNITAID.
Journal Article
Pharmaceutical cost dynamics for the treatment of rifampicin-resistant tuberculosis in children and adolescents in South Africa, India, and the Philippines
by
Seddon, James. A.
,
Sinanovic, Edina
,
Paradkar, Mandar
in
Acceptability
,
Adolescent
,
Adolescents
2024
Rifampicin-resistant (RR) tuberculosis (TB) in children is a major global health concern but is often neglected in economics research. Accurate cost estimations across the spectrum of paediatric RR-TB treatment regimens are critical inputs for prioritisation and budgeting decisions, and an existing knowledge gap at local and international levels. This normative cost analysis was nested in a Phase I/II pharmacokinetics, safety, tolerability, and acceptability trial of TB medications in children in South Africa, the Philippines and India. It assessed the pharmaceutical costs of 36 childhood RR-TB regimens using combinations from 16 different medicines in 34 oral formulations (adult and child-friendly) in 11 weight bands in children <15 years of age. The analysis used local and Global Drug Facility pricing, and local and international guideline recommendations, including adaptions of BPaL and BPaLM regimens in adults. Costs varied significantly between regimen length, age/weight banding, severity of disease, presence of fluroquinolone resistance, and different country guideline recommendations. WHO recommended regimen costs ranged 12-fold: from US $232 per course (short regimen in non-severe disease) to US$ 2,761 (long regimen in severe, fluroquinolone-resistant disease). Regimen treating fluoroquinolone-resistant infection cost US $1,090 more than comparable WHO-recommended regimen. Providing child-friendly medicine formulations in <5-year-olds across all WHO-recommended regimens is expected to cost an additional $ 380 (range$212-$ 563) per child but is expected to have wider benefits including palatability, acceptability, adherence, tolerability, and dose accuracy. There were substantial differences in regimen affordability between countries when adjusted for purchasing power and domestic spending on health. Appropriate, effective, and affordable treatment options are an important component of the fight against childhood RR-TB. A comprehensive understanding of the cost and affordability dynamics of treatment options will enable national TB programs and global collaborations to make the best use of limited healthcare resources for the care of children with RR-TB.
Journal Article
The Wonder Years: What Can Primary School Children Teach Us About Immunity to Mycobacterium tuberculosis?
2018
In high burden settings, the risk of infection with
increases throughout childhood due to cumulative exposure. However, the risk of progressing from tuberculosis (TB) infection to disease varies by age. Young children (<5 years) have high risk of disease progression following infection. The risk falls in primary school children (5 to <10 years), but rises again during puberty. TB disease phenotype also varies by age: generally, young children have intrathoracic lymph node disease or disseminated disease, while adolescents (10 to <20 years) have adult-type pulmonary disease. TB risk also exhibits a gender difference: compared to adolescent boys, adolescent girls have an earlier rise in disease progression risk and higher TB incidence until early adulthood. Understanding why primary school children, during what we term the \"Wonder Years,\" have low TB risk has implications for vaccine development, therapeutic interventions, and diagnostics. To understand why this group is at low risk, we need a better comprehension of why younger children and adolescents have higher risks, and why risk varies by gender. Immunological response to
is central to these issues. Host response at key stages in the immunopathological interaction with
influences risk and disease phenotype. Cell numbers and function change dramatically with age and sexual maturation. Young children have poorly functioning innate cells and a Th2 skew. During the \"Wonder Years,\" there is a lymphocyte predominance and a Th1 skew. During puberty, neutrophils become more central to host response, and CD4+ T cells increase in number. Sex hormones (dehydroepiandrosterone, adiponectin, leptin, oestradiol, progesterone, and testosterone) profoundly affect immunity. Compared to girls, boys have a stronger Th1 profile and increased numbers of CD8+ T cells and NK cells. Girls are more Th2-skewed and elicit more enhanced inflammatory responses. Non-immunological factors (including exposure intensity, behavior, and co-infections) may impact disease. However, given the consistent patterns seen across time and geography, these factors likely are less central. Strategies to protect children and adolescents from TB may need to differ by age and sex. Further work is required to better understand the contribution of age and sex to
immunity.
Journal Article
Understanding the interaction between cytomegalovirus and tuberculosis in children: The way forward
by
Stockdale, Lisa
,
Olbrich, Laura
,
Seddon, James A.
in
Adolescent
,
Antigens
,
Biology and Life Sciences
2021
Over 1 million children develop tuberculosis (TB) each year, with a quarter dying. Multiple factors impact the risk of a child being exposed to Mycobacterium tuberculosis ( Mtb ), the risk of progressing to TB disease, and the risk of dying. However, an emerging body of evidence suggests that coinfection with cytomegalovirus (CMV), a ubiquitous herpes virus, impacts the host response to Mtb , potentially influencing the probability of disease progression, type of TB disease, performance of TB diagnostics, and disease outcome. It is also likely that infection with Mtb impacts CMV pathogenesis. Our current understanding of the burden of these 2 diseases in children, their immunological interactions, and the clinical consequence of coinfection is incomplete. It is also unclear how potential interventions might affect disease progression and outcome for TB or CMV. This article reviews the epidemiological, clinical, and immunological literature on CMV and TB in children and explores how the 2 pathogens interact, while also considering the impact of HIV on this relationship. It outlines areas of research uncertainty and makes practical suggestions as to potential studies that might address these gaps. Current research is hampered by inconsistent definitions, study designs, and laboratory practices, and more consistency and collaboration between researchers would lead to greater clarity. The ambitious targets outlined in the World Health Organization End TB Strategy will only be met through a better understanding of all aspects of child TB, including the substantial impact of coinfections.
Journal Article
Turning off the tap: stopping tuberculosis transmission through active case-finding and prompt effective treatment
by
Keshavjee, Salmaan
,
Yuen, Courtney M
,
Amanullah, Farhana
in
Cross Infection - prevention & control
,
Cross Infection - transmission
,
Disease control
2015
To halt the global tuberculosis epidemic, transmission must be stopped to prevent new infections and new cases. Identification of individuals with tuberculosis and prompt initiation of effective treatment to rapidly render them non-infectious is crucial to this task. However, in settings of high tuberculosis burden, active case-finding is often not implemented, resulting in long delays in diagnosis and treatment. A range of strategies to find cases and ensure prompt and correct treatment have been shown to be effective in high tuberculosis-burden settings. The population-level effect of targeted active case-finding on reducing tuberculosis incidence has been shown by studies and projected by mathematical modelling. The inclusion of targeted active case-finding in a comprehensive epidemic-control strategy for tuberculosis should contribute substantially to a decrease in tuberculosis incidence.
Journal Article
Experiences of children and their caregivers affected by multidrug-resistant tuberculosis in Cape Town, South Africa
2025
Approximately 30,000 children (<15 years) develop multidrug-resistant (MDR) tuberculosis (TB) each year. MDR-TB severely impacts the lives of children and their families, yet data exploring their experiences are limited. We describe the experiences of children routinely treated for MDR-TB and their caregivers throughout their MDR-TB journeys in Cape Town, South Africa.
We conducted a series of three in-depth qualitative interviews (48 interviews in total) with 17 children (<15 years) and/or their caregivers between April 2021 and September 2021. We selected children who had been routinely treated for MDR-TB between 2018 and 2021. We applied a deductive, thematic analysis to case summaries with illustrative examples from interviews.
Children had negative experiences throughout their MDR-TB journey, before their diagnosis, during the diagnostic process, through treatment, and beyond treatment completion. Children and their caregivers experienced delays in acquiring accurate and timely MDR-TB diagnosis; stating lack of symptom recognition and repeated referrals between health facilities. Once on treatment, caregivers experienced challenges administering MDR-TB medication as children resisted taking their medications due to poor palatability, tolerability, and negative side effects. Some caregivers reported that, beyond treatment, children experienced extended physical challenges such as shortness of breath. Additionally, MDR-TB diagnosis and treatment negatively affected family life, as caregivers adjusted household spending toward foods that facilitated ingestion and mitigated side effects. Caregivers also juggled between attending to their children's MDR-TB care and other household priorities.
There are multifactorial challenges experienced by children and their caregivers throughout their MDR-TB journey. Research is needed to develop holistic interventions for child-caregiver-centred psychosocial support to mitigate the negative impact of MDR-TB on children and their caregivers through prevention, earlier diagnosis, and simpler, child-friendly regimens. [1112,3].
Journal Article
Practical and psychosocial challenges faced by caregivers influence the acceptability of multidrug-resistant tuberculosis preventive therapy for young children
by
Reis, Ria
,
Seddon, James A.
,
Hoddinott, Graeme
in
Acceptability
,
Antibiotics
,
Antitubercular Agents - adverse effects
2022
Drug-resistant (DR) strains of Mycobacterium tuberculosis ( M . tb ) are increasingly recognised as a threat to global tuberculosis (TB) control efforts. Identifying people with DR-TB exposure/ infection and providing TB preventive therapy (TPT) is a public health priority. TB guidelines advise the evaluation of household contacts of newly diagnosed TB cases, with the provision of TPT to vulnerable populations, including young children (<5 years). Many children become infected with TB through exposure in their household. Levofloxacin is under evaluation as TPT in children exposed to M . tb strains with resistance to rifampicin and isoniazid (multidrug-resistant TB; MDR-TB). Prior to opening a phase 3 prevention trial in children <5 years exposed to MDR-TB, the pharmacokinetics and safety of a novel formulation of levofloxacin given daily was evaluated as part of a lead-in study. We conducted an exploratory qualitative study of 10 caregivers’ experiences of administering this formulation. We explored how the acceptability of levofloxacin as TPT is shaped by the broader impacts of MDR-TB on the overall psychological, social, and financial wellbeing of caregivers, many of whom also had experienced MDR-TB. Caregivers reported that the novel levofloxacin formulation was acceptable. However, caregivers described significant psychosocial challenges in the process of incorporating TPT administration to their children into their daily lives, including financial instability, withdrawal of social support and stigma. When caregivers themselves were sick, these challenges became even more acute. Although new child-friendly formulations can ameliorate some of the pragmatic challenges related to TPT preparation and administration, the overall psychosocial burden on caregivers responsible for administering TPT remains a major determinant of effective MDR-TB prevention in children.
Journal Article
Treatment outcomes for children with multidrug-resistant tuberculosis: a systematic review and meta-analysis
by
Schaaf, H Simon
,
Ettehad, Dena
,
Seddon, James A
in
Antitubercular Agents - adverse effects
,
Antitubercular Agents - therapeutic use
,
Bacterial diseases
2012
Paediatric multidrug-resistant (MDR) tuberculosis is a public health challenge of growing concern, accounting for an estimated 15% of all global cases of MDR tuberculosis. Clinical management is especially challenging, and recommendations are based on restricted evidence. We aimed to assess existing evidence for the treatment of MDR tuberculosis in children.
We did a systematic review and meta-analysis of published and unpublished studies reporting treatment outcomes for children with MDR tuberculosis. We searched PubMed, Ovid, Embase, Cochrane Library, PsychINFO, and BioMedCentral databases up to Oct 31, 2011. Eligible studies included five or more children (aged ≤16 years) with MDR tuberculosis within a defined treatment cohort. The primary outcome was treatment success, defined as a composite of cure and treatment completion.
We identified eight studies, which reported treatment outcomes for a total of 315 patients. We recorded much variation in the characteristics of patients and programmes. Time to appropriate treatment varied from 2 days to 46 months. Average duration of treatment ranged from 6 months to 34 months, and duration of follow-up ranged from 12 months to 37 months. The pooled estimate for treatment success was 81·67% (95% CI 72·54–90·80). Across all studies, 5·9% (95% CI 1·3–10·5) died, 6·2% (2·3–10·2) defaulted, and 39·1% (28·7–49·4) had an adverse event. The most common drug-related adverse events were nausea and vomiting. Other serious adverse events were hearing loss, psychiatric effects, and hypothyroidism.
The treatment of paediatric MDR tuberculosis has been neglected, but when children are treated outcomes can be achieved that are at least as good as those reported for adults. Programmes should be encouraged to report outcomes in children to improve the knowledge base for care, especially as new drugs become available.
None.
Journal Article
Mortality during tuberculosis treatment in South Africa using an 8-year analysis of the national tuberculosis treatment register
by
Dunbar, Rory
,
Claassens, Mareli M.
,
Seddon, James A.
in
692/499
,
692/699/255/1856
,
692/699/255/1901
2021
In 2011, the South African HIV treatment eligibility criteria were expanded to allow all tuberculosis (TB) patients lifelong ART. The impact of this change on TB mortality in South Africa is not known. We evaluated mortality in all adults (≥ 15 years old) treated for drug-susceptible TB in South Africa between 2009 and 2016. Using a Cox regression model, we quantified risk factors for mortality during TB treatment and present standardised mortality ratios (SMR) stratified by year, age, sex, and HIV status. During the study period, 8.6% (219,618/2,551,058) of adults on TB treatment died. Older age, male sex, previous TB treatment and HIV infection (with or without the use of ART) were associated with increased hazard of mortality. There was a 19% reduction in hazard of mortality amongst all TB patients between 2009 and 2016 (adjusted hazard ratio: 0.81 95%CI 0.80–0.83). The highest SMR was in 15–24-year-old women, more than double that of men (42.3 in 2016). Between 2009 and 2016, the SMR for HIV-positive TB patients increased, from 9.0 to 19.6 in women, and 7.0 to 10.6 in men. In South Africa, case fatality during TB treatment is decreasing and further interventions to address specific risk factors for TB mortality are required. Young women (15–24-year-olds) with TB experience a disproportionate burden of mortality and interventions targeting this age-group are needed.
Journal Article
A clinical practice guideline for tuberculous meningitis
2025
Tuberculous meningitis is the most severe form of tuberculosis, causing death or disability in around half of those affected. There are no up-to-date international guidelines defining its optimal management. Therefore, the Tuberculous Meningitis International Research Consortium conducted a systematic review of available evidence to address key management questions and to develop practice guidance. The consortium includes representatives from India, Indonesia, South Africa, Uganda, Viet Nam, Australia, the Netherlands, the UK, and the USA. Questions were developed using the Population, Intervention, Comparator, Outcome (PICO) format for tuberculous meningitis diagnosis, anti-tuberculosis chemotherapy, adjunctive anti-inflammatory therapy, and neurocritical and neurosurgical care. A Grading of Recommendations, Assessment, Development and Evaluations approach was used to assess the certainty (or quality) of evidence and establish the direction and strength of recommendations for each PICO-based question. We provide evidence-based recommendations for the optimal treatment and diagnosis of tuberculous meningitis, alongside expert opinion. We expose substantial knowledge and evidence gaps, thereby highlighting current research priorities.
Journal Article